1. Technical Field
The present invention relates to a technique for performing an open/close judgment of an opening of a device.
2. Related Art
An ink jet printer includes an opening for performing, for example, attachment and detachment of an ink cartridge, and a cover for opening and closing the opening. The ink jet printer generally has a judgment device for performing a judgment of whether or not the opening is closed (open/close judgment of the opening) in order to, for example, avoid execution of print operation while the opening is opened. The judgment device for performing the open/close judgment of the opening may be, for example, an open/close sensor having a sensor lever that is interfered with a cover to be displaced when the opening is closed by the cover, and a detection unit for detecting the displacement of the sensor lever is used (for example, see JP-A-2006-264160).
When a conventional open/close sensor is used as the judgment device for performing the open/close judgment of the opening, even when the opening is slightly opened due to a variation or the like of a contact point of the open/close sensor, it is possible that the opened state can not be detected for judging that the opening is closed. Further, there is a risk that the open/close state of the opening is misjudged, since the open/close sensor judges that the opening is closed even when the sensor lever is interfered with an object, which is not the cover to be displaced. In this manner, in the conventional judgment device for performing the open/close judgment of the opening, there is room for improving the judgment accuracy.
Note that such a problem is not limited to the open/close judgment of the opening through which attachment and detachment of an ink cartridge equipped in an ink jet printer is performed, and is a common problem in the case where the open/close judgment of an opening included in a device is performed.